Ventilated container

ABSTRACT

The invention provides a container ( 1 ) comprising an outer receptacle ( 2 ) and, disposed therein, an inner receptacle ( 6 ) in the form of a bag; the bag being permeable to gases; the outer receptacle having a plurality of spacers ( 8 ) extending inwardly from an inner surface ( 9 ) thereof, and a plurality of vents ( 10 ) in the walls ( 9 ) of the outer receptacle ( 2 ); the spacers ( 8 ) serving to support the inner bag ( 6 ) such that it is spaced apart from the inner surface ( 9 ) of the outer receptacle ( 2 ); and the vents ( 10 ) serving to allow air to circulate between the bag ( 6 ) and the outer receptacle ( 2 ).

The present invention relates to a container, and in particular to acontainer for use in the collection and storage of materials.

A major problem facing most communities is the problem of wastedisposal. Each day vast quantities of waste are created, and such wastemust be removed and processed in a safe and hygienic manner.

For waste materials storage and collection, the main choices open otherthan disposal of the waste are either incineration to generate energy,or separation of the waste material into fractions for recycling orcomposting or anaerobic digestion. In order to help encourage theco-operation of householders and other generators of waste materials toseparate waste at source in a way which helps the processor of the wasteto produce what the market demands, many local authorities now provideoutside waste material collection bins.

Organic waste presents particular problems due in large part to the highmoisture content of the waste. In warmer weather conditions, unless thewaste is adequately vented, unpleasant odours can build up quickly asanaerobic conditions are set up in the waste collection bins.

The cost of collection of waste materials can be significant and oneoption open to waste collection authorities to reduce the cost ofcollections is to reduce the frequency of the collections. However, itwill be appreciated that if the waste is left for longer periods, odourlevels can become unacceptably high.

In addition to the problem of anaerobic decomposition, a further problemfacing the collector of waste materials is the problem of infestation byvermin, insects and other small creatures.

There have been a number of disclosures by others relating to wastecollection or storage bins providing an aerobic environment but suchbins are considered to have significant limitations as to theirusefulness and effectiveness.

European Patent Application No. 92610025 discloses a rubbish bag holderwhich requires a specially designed cart to transport the holder to acollection vehicle for emptying. One consequence of this is that the bagcannot be used with existing collection vehicle lifting gear generallyin use in many areas. Moreover, the time taken for a contractor to emptythe bag holder and move onto the next is greater than if the bag holderhas its own wheels.

WO-A-95/01294 discloses a rather complicated arrangement which consistsof an outer receptacle, an inner perforated supporting bag, and, withinthe supporting bag, an inner paper bag. In the more complex, andseemingly preferred, arrangements disclosed in WO-A-95/01294, there isadditionally an inner insert container in the form of a laundry-basketlike arrangement thus making a total of four nested containers in total.

U.S. Pat. No. 5,031,796 discloses a ventilated waste container,containing several relatively small arrays of vent holes at the upperand lower ends of the container. The container has vertical ribs whichprotrude inwardly from the walls of the container to function asspacers, the intention being that the spacers should prevent wastewithin the container coming into close contact with walls. However, thecontainer of U.S. Pat. No. 5,031,796 is not specifically designed foruse with inner liner bags, and as a consequence, the spacers would onlybe of value for a narrow range of materials. Along with the spacers, theuse of a grate on which the material is to be disposed also limits therange of material which can be deposited in the container, requiring theavoidance of cooked food and other material reduced to small fragments.The aim is only to deposit material which will not fall through thegrate or prevent/limit the migration of air through or round thematerial, thus encouraging the development of anaerobic conditions.

It is an object of the present invention to provide an outer receptacleor container which can be used to contain an air permeable inner liner,such as a paper sack, in a manner which provides for effective ventingand air circulation between the outer container and the inner liner.

it is a further object of the invention to provide a container which isof relatively simple construction and is therefore relativelyinexpensive and easy to fabricate.

Accordingly, in a first aspect, the invention provides a containercomprising an outer receptacle and, disposed therein, an innerreceptacle in the form of a bag, the bag being permeable to gases, theouter receptacle having a plurality of spacers extending inwardly froman inner surface thereof, and a plurality of vents in the side wallsand/or the base of the outer receptacle, the spacers serving to supportthe inner bag such that it is spaced apart from the inner surface of theouter receptacle, and the vents serving to allow air to circulatebetween the bag and outer receptacle.

The container can be a container intended for use in the temporarystorage of waste materials, such as household, domestic, business orindustrial waste, but it can also be used for the storage of othermaterials which would benefit from the improved ventilation propertiesof the invention.

The purpose of the vents and spacers inter alia is to ensure that thereis sufficient air movement between the outer and inner receptacles toavoid setting up anaerobic conditions. The shape, configuration,frequency and dimensions of the spacers and vents can vary according tothe particular circumstances in which the container is to be used, andcan depend for example on the number of air changes required for a givenset of temperature assumptions, the nature of the material or productcontained in the bag, and the specification of the bag.

The vents typically are provided adjacent at least 10% and more usuallyat least 25% of the spacers, and preferably are provided adjacent atleast 30%, for example at least 50%, and most preferably at least 75%,e.g. up to 100% of the spacers.

The vents typically are elongate in form and can be, for example,arranged in a plurality of substantially horizontal or vertical rowsaround the outer receptacle. Advantageously there are at least two andpreferably at least three such rows. The rows can be parallel withrespect to each other, and can be disposed such that the vents are insubstantially vertical or horizontal alignment. Alternatively, the rowscan be staggered.

Horizontally adjacent spacers can have a single vent therebetween, or aplurality of vents, for example two, three or four vents. The number ofvents disposed between the pairs of adjacent spacers around the wall ofthe outer receptacle can the same for all spacers, or can differ.

In one embodiment, the side walls have no vents, but instead the ventsare located at the base of the outer receptacle, as described below.

In another embodiment, the vents are arranged in rows at regularspacings down the height of the outer receptacle.

In a still further embodiment, vents are located only on the base and atthe upper end of the side walls of the receptacle.

In each of the aforesaid embodiments, the numbers and positions of thevents, as well as their shape and size, are typically chosen so as topermit free flow of air, by convection currents, from the bottom of thecontainer to the top. Thus, although it is preferred that the side wallshould contain vents, it is possible to omit vents from at least thelower ends of the side walls provided that the base is adequately ventedand vents are provided at the upper end of the side wall and/or on anylid. It is most preferred however that any vents at the upper end of thecontainer are on the side wall rather than on the lid, so at reduce theopportunities for ingress of rain water and pests such as flies.

The vertical distance between rows of vents can be, for example, between0.1 and 3 times (for example from 0.25 to 2 times) the height of eachvent in a pair of vertically adjacent rows. Where the vents invertically adjacent rows are of differing height, the vertical distancebetween them, as defined above, refers to the average height of thevents.

The horizontal distance between adjacent vents in a row of vents can be,for example, between 1 and 50 times the width of the vent, for examplebetween 2 and 25 times the width of the vent. Where adjacent vents ofare of different width, the definition of the horizontal distancebetween them set out above refers to the average width of the relevanttwo adjacent vents.

The spacers can be in the form of elongate ribs. The configuration andarrangement of the spacers is preferably such that, together with theinner surface of the outer receptacle and the outer surface of the innerreceptacle or bag, elongate ducts are created which serve to channelconvection currents between the inner and outer receptacles.

The elongate spacers preferably extend in a substantially upwardsdirection, and most preferably are substantially vertical. Consequently,the ducts formed by the spacers extend in a substantially upwards andpreferably substantially vertical direction.

The spacers can extend upwardly without interruption, from a location ator adjacent the lower end of the container, or there can bediscontinuities in the spacers. Such discontinuities enable lateralmovement of air currents as well as movement in an ascending ordescending direction. Moreover, by making the spacers, and hence theducts, relatively short, resistance to air movement through the ductscan be minimised.

Where the spacers are discontinuous, they can be, for example, arrangedin a plurality of substantially horizontal rows around the inner surfaceof the outer receptacle. For example, there can be at least two suchhorizontal rows, e.g three or more such rows. The rows can be parallelwith respect to each other, and can be disposed such that the spacersare in substantially vertical alignment. Alternatively, the rows can bestaggered.

Vents can be present between the spacers in all rows, or only some ofthem, or none of them. For example, where the spacers are arranged in aplurality of rows, vents may be located between the spacers in only theuppermost row, or the uppermost two rows (where there are more than tworows).

In accordance with the invention, an even flow of air through thecontainer between the bag and the inner face of the outer receptacle canbe achieved by ensuring that the resistance to flow of air through theair ducts balances the resistance to flow of air through the ventsthrough which the air moves out of the container. The resistance to airflow through the ducts can be controlled by controlling the dimensionsof the spacers, and the distances between them. For example, in order toreduce resistance to air flow, the spacers can be made shorter and/orthe distances between adjacent spacers increased and/or the depth of thespacers (i.e. the distance by which they protrude inwardly) can beincreased. However, this must balanced against the requirements imposedby the material from which the bag is made and/or the materials whichare to be contained in the bag. By ensuring that the amount of supportgiven by the spacers takes into account the properties of the bag andcontents of the bag, bulging of the bags into the ducts required forventilation is minimised to avoid a restriction in the flow of air.

By way of example, the spacers can be from 0.25 cm to 15 cm apart andcan have a depth of from 0.25 cm to 8 cm, the term “depth” referring tothe distance by which the spacers protrude inwardly from the walls ofthe container. Thus the ducts created between the inner and outerreceptacles can have a cross sectional area of, for example, 0.06 cm² to120 cm₂. The spacers can have a width varying from, for example, 0.25 cmto 5 cm.

The ventilation system defined by the arrangement of spacers and ventsset out above stimulates an air flow through the container by harnessingthe natural convection of air within the container set up by temperaturegradients between the outer receptacle and the inner receptacle bag andbetween the top and bottom of the container, or by the heating orcooling of the container to temperatures different from that of thesurrounding air by, for example, solar radiation. By regulating, forexample, the length of the columns of air in the ducts formed by theinside face of the container, spacers and inner receptacle, or thecross-sectional area and shape of the column of air, and the colour andfinish of the container, it is possible to design the ventilation systemto provide a given number of air changes per period of time for a givenset of temperature conditions in and outside the container.

In order to take advantage of the effect of solar radiation on thetemperature of the container, and hence the rate of convection, thecolour and finish of the outer and inner receptacle can be varied. Forexample, in order to increase radiation absorption, the outer and/or theinner receptacle can be provided in dark colour, e.g. black.

An advantage of the ventilation system of the invention is that the airmovement does not rely on either mechanical means of forcing air throughthe container, movement of air outside the container, or a heat sourceprovided by the contents, and in this respect, the invention isdistinguished from the prior art cited above. Nevertheless, bypositioning the vents in the sides, the container is also designed tofacilitate an even air flow through the ducts around the hole containerby forced convection when windy conditions prevail, and also to takeadvantage of a heat source if provided by the contents or other means togenerate air movement by convection.

A further advantage of the present invention is that it does not requireany intervening structure (other than the spacers) between the outer andinner receptacles. In this respect, the invention is furtherdistinguished from the container disclosed in WO-A-95/01294 whichrequires a reusable permeable supporting bag, and preferably also a“laundry basket” type structure between the outer receptacle and thepaper sacks in which the household waste is actually carried.

In order to assist convective air flow from the bottom of the containerto the top, the outer receptacle typically is provided with a basehaving at least one vent and more usually a plurality of vents therein.

The vents can be of any size or shape consistent with the requirementfor structural integrity, but preferably are sized so as to prevent theingress of rodents or other unwanted intruders. The vents can be, forexample, circular or non-circular, for example of elongate or slottedform, or of ovoidal or polygonal (regular or irregular) form. The ventscan be for example from 4 mm to about 8 mm in width or diameter, incircumstances where it is desired to prevent the ingress of rodents. Incircumstances where ingress of rodents is not a problem, the size andshape of the vents in the base will depend on inter alia the structuralintegrity of the container and/or the level of support required for theinner receptacle or bag.

The base of the outer receptacle can be formed integrally with the sidewalls, for example in a single moulding, or it can be formed separately.Where it is formed separately, it can take the form of a grating or gridor an insert (preferably vented) which rests in, or is secured in, thelower end of the outer receptacle. Thus, the lower end of the receptaclecan be provided with a ledge or other support surface upon which thegrid can rest. Alternatively, or additionally, a false bottom can beprovided in the outer receptacle in the form of an insert, grid orgrate, which can be fixed permanently in place or constructed so as tobe removable.

The resistance of air flow at the bottom of the container is minimisedby providing as large an area of vents as is possible, consistent withmaintaining the structural integrity of the container, and preventaccess of rodents and other living things. For example, the area of thevents can be from up to 95% (for example 10% to 95%), typically 20% to80%, more usually up to 70% of the total area of the base, e.g. from 40%to 60%.

The lower end of the outer receptacle can be provided with means forspacing the base from an underlying surface so as to prevent obstructionof the vents by the underlying surface. The means for spacing the basefrom the underlying surface can take the form of, for example, a wheelor wheels and/or a leg or legs.

It is preferred that the top of the container will have a lid which mayhave vents, or a rain-proof cowl to draw air through the container, orother ventilation means. The lid is preferably hingedly connected to theouter receptacle. In one embodiment, the lid comprises a plurality (e.g.a pair) of lid members, each hingedly connected to the outer receptacle.

The outer receptacle can contain one bag or a plurality of bags. Wherethe containment of multiple bags is envisaged, the outer receptacle canbe provided with dividers for dividing the interior of the receptacleinto compartments, each compartment being intended to contain one ormore inner receptacles or bags.

The or each bag can be formed from a paper material, or a permeablepolymeric or composite material, for example. The bag can contain aliner or have a surface (e.g. the inner surface) treated (e.g. coated)to alter its strength and/or permeability characteristics to enable itto contain certain types of material more efficiently. The bag can beformed from a material such as paper or another material which isinherently permeable, or it can be formed, for example, from animpermeable material which has been perforated (preferablymicroperforated or fibrillated) to give it the necessary permeability.One example of such a material is a needled plastics (e.g. polyethylene)film. It will be appreciated that the bag will be formed from a materialwhich is appropriate for the circumstances of its use, and for examplethe characteristics and structural features of the outer receptacle.Thus, for example, if the bag is to be formed from a relatively weakmaterial, or a material such as recycled paper which has reducedstructural integrity upon wetting, the outer receptacle typically willneed to provide a greater degree of support to the bag, in terms ofnumbers and densities of the spacers, than would be required for arelatively durable material such as a Kraft paper.

The bag can be permeable to liquids (such as water), and most preferablyis permeable to liquids in vapour form, such as water vapour. The liquidand/or vapour permeability can be unidirectional or bidirectional. Wherethe permeability is unidirectional, it is typically oriented such thatliquid and/or vapour passes from the interior of the bag to itsexterior. When a permeable bag is filled with moisture laden organicwaste, for example, the outer surface of the bag will become wet, butthe shedding of liquids from the bag can generally be avoided by thedrying properties of air migrating through the container between theouter receptacle and the bag.

The bag can also be permeable to hydrocarbons, either undirectionally orbidirectionally as aforesaid in relation to liquids and vapours ingeneral.

It will be appreciated from the foregoing that the properties of theinner receptacle which can be exploited include the ability of vapours,gases and liquids to migrate through the inner receptacle, either inboth directions, or uni-directionally. Variation in the structuralstrength of the bags available can be accommodated by varying the amountof support given by the spacers. For example, a paper sack of a givenweight and specification of paper containing damp compostable organicwaste will require more support from spacers in keeping the surface ofthe sack away from the inside faces of the outer receptacle than asimilar sack containing a dry product of similar weight distribution.

The outer receptacle of the container preferably has suspension meansfor securing the inner receptacle to an upper end thereof. Thesuspending means is preferably arranged to hold the inner receptacle orbag in an open configuration. Alternatively, or additionally, the baseof the container can be provided with one or more spacer elements forsupporting the bag. The spacer(s) can take the form of a platform forsupporting the bag. Where the base of the outer receptacle is vented, itis preferred that any such platform is constructed so as not tointerfere substantially with the movement of air up through thecontainer. In one embodiment, the lower end of the container can beprovided with a tray (e.g. a removable tray) for collecting liquidsseeping from the inner receptacle or bag.

In order to assist movement of the container, the outer receptacle ispreferably provided with means defining a handle or other formation toenable the container to be lifted or moved.

In addition to the combination of inner and outer receptacles, theinvention also relates to the outer receptacles per se.

It is envisaged that the containers of the invention will findapplication not only in the storage, management and collection of wastematerials, but also in other fields in which the protection of moisturesensitive materials is considered desirable, for example in the fieldsof textiles, food, chemicals and pharmaceutical and bulk materials, andin particular fields in which the protection of the contents, and thehandlers of the containers, is of importance. In the field of wastemanagement, the container can be for example, a domestic waste containerof the “wheelie bin” or “dustbin” variety, intended for use outdoors, orit can be for example a kitchen waste bin.

One further problem facing users of waste containers and, indeed, wastecollection contractors, is the problem of infestation of the waste withinsects and small creatures. In order to overcome or avoid this problem,either the outer receptacle or the bag, or both, can be provided withmeans for repelling and/or killing insects and small creatures. Forexample, the inner bag can be dipped, sprayed, painted, coated orimpregnated with a suitable composition for repelling and/or killinginsects and small creatures. Such compositions can be example chosenfrom organophosphorus compounds, or the pyrethroids, or compounds suchas diethyltoluamide, or essential oils, or larvicidal compounds such ascyromazine.

Instead of, or in addition to, treating the inner bag with compounds orcompositions for repelling and/or killing insects and small creatures,the outer receptacle can be provided with means for holding ordispensing such compositions or compounds. For example, a suitableholder can be mounted on the underside of the lid of the outerreceptacle; an advantage of this arrangement being that it deters fliesand other pests from entering the container as the lid is lifted. Theholder can contain a matrix or substrate containing or coated with asuitable repellant or insecticidal composition. Alternatively, oradditionally, a suitable holder can be mounted on, or incorporated intothe side walls or base of the outer receptacle, preferably in the lowerpart (e.g. lower third) of the outer receptacle.

It is envisaged that the provision of a holder or dispenser secured tothe underside of the lid of a waste container, or to the side wails orbase of the container will be generally applicable to waste containersand indeed containers in general, and not merely to the containers ofthe present invention. Accordingly, in a further aspect, the inventionprovides a container (e.g. a waste container) having a main containerbody and a lid, preferably hingedly mounted thereon, the lid or the maincontainer body, or both, having mounted thereon, or having incorporatedtherein, a holder or support containing or bearing a composition forrepelling and/or killing insects or small creatures.

Such compositions can be example chosen from organophosphorus compounds,or the pyrethroids, or compounds such as diethyltoluamide, or essentialoils, or larvicidal compounds such as cyromazine.

The invention will now be illustrated by way of example by reference tothe particular embodiments shown in the accompanying drawings of which:

FIG. 1 shows a cut-away diagram of the outer receptacle in a wheeled binconfiguration, in which the bag is suspended in the outer receptacle;

FIG. 2 shows a horizontal slice through the container depicted in FIG. 1on the line marked A—A;

FIG. 3 similarly shows a slice through the container depicted in FIG. 1,but this time on the line Y—Y;

FIG. 4 shows a cut-away diagram of the outer receptacle in a chestconfiguration;

FIG. 5 shows a side elevation of the lower half of a container in whicha ventilated insert has been placed;

FIG. 6 shows the container of FIG. 5 from above with the insert inplace;

FIG. 7 shows a cut-away diagram of the outer receptacle in aconfiguration suitable for a kitchen bin;

FIGS. 8a to 8 f are schematic illustrations showing various arrangementsof spacers and vents;

FIG. 9 is a sectional elevation of a container according to anotherembodiment of the invention;

FIG. 10 is a view from above of the container of FIG. 9, but with thelid opened or removed;

FIG. 11 is a sectional elevation of a container according to a stillfurther embodiment of the invention; and

FIG. 12 is an enlarged view of a portion of the container of FIG. 11.

FIG. 1 shows a cut-away diagram of the outer receptacle 2 in a wheeledbin configuration which is provided with an openable lid 3, sides 4 anda bottom face 5. The bag 6 is suspended in the outer receptacle andsecured at the top of the outer receptacle 2 by suspension means 7. Thesubstantially vertical spacers 8 which run parallel to each other fromtop to bottom of the sides 4 hold the bag 6, in this embodiment a papersack made of kraft paper, away from the inside face of the side walls 9of the outer receptacle 2. Except at the corners between two sides 4 thevents 10 in this embodiment are arranged between each adjacent pair ofspacers 8 are placed down the length of the sides as well as the bottomface 5 of the outer receptacle 2. The bag 6 shown in this embodiment ismanufactured to a specification in which it is not necessary for itsbase 11 to be supported by the bottom face 5 of the outer receptacle. Inthis embodiment the total length of the vents 10 cover typically 50 to60% of the total length of each side 4 arranged evenly from top tobottom of the container 1 and the width of each vent in this embodimentwill be typically 4 mm to stop access to rodents. The spacers 8 in thesides 4 in this embodiment are typically around 15 mm apart. A pair ofwheels 15 are provided.

FIG. 2 shows a horizontal slice through the container depicted in FIG. 1on the line marked A—A. It shows the side 4 of the outer receptacle, theposition of the spacers 8 and the vent 10, and the bag 6 which is beingheld away from the inside face of the outer receptacle. The radius ofeach side of the opening 12 is proportionately large to make itdifficult for a rodent to gain a purchase to gnaw its way through theouter receptacle 2.

FIG. 3 similarly shows a slice through the container depicted in FIG. 1,but this time on the line Y—Y. It shows a vertical slice through thecontainer demonstrating the position of the vents 10 and spacers 8. Thebag 6 is shown retained by suspension means 7 at the mouth of thecontainer and held away from the inside face of the side wall 9 of thecontainer.

FIG. 4 is a container 1 which shows a cut-away diagram of the outerreceptacle 2 in a chest configuration, equipped with a hinged lid 3. Thespacers 8 and vents 10 are shown evenly distributed along the insideface of the side walls 9 of the outer receptacle 2, with a ventilationgrid 13 shown above the pair of removable trays 14 which can be insertedif it is necessary to capture solids or liquids discharged from thematerial stored in the container. The vents 10 can, if necessary, becontained in the bottom face 5 of the outer receptacle. This embodimentshows the bags 6 placed in the container without the need for anysuspension means. For waste materials storage and collection themeasurements and the need to consider rodents will apply as in the caseof FIG. 1. However, the size of the vents and spacers can be larger forcertain industrial uses, dictated by the point loading capacity of thebags in use and degree of ventilation required. In this embodimentwheels 15 at each corner are included.

FIG. 5 shows a side elevation of the lower half of a container 1 in awheeled bin configuration in which an insert 16 has been placed,enabling the container to be used with a smaller capacity bag. With theinsert with vents 10 included, the outer receptacle is able to providesupport to the base of a shorter bag 6. In this example, use is made ofthe vents in the base of the container in retaining the fastening 17 onthe insert in place.

FIG. 6 shows the container 1 of FIG. 5 from above with the insert inplace. The insert 16 is positioned inside the side wall spacers 8. Theinsert is shown with vents 10 in its top face enabling substantially thesame level of air circulation in the container for the base of theshorter bag.

FIG. 7 shows a cut-away diagram of the outer receptacle 2 in aconfiguration suitable for a kitchen bin with hinged lid 3 andsuspension means 7 for holding the bag 6 open at the top end of thecontainer. In this embodiment the bag 6 is a paper sack which is assumedto be manufactured to a specification in which it is necessary for itsbase to be supported. The substantially vertical spacers 8 hold the bagaway from the inside face of the side walls 9 of the outer receptacle 2with a regular distribution of vents 10 in between. In this example, thecontainer has been designed with an integral tray 14 to catch anyliquids or solids, but also has bottom face 5 vents 10 which ring thetray to bring some ventilation to the base of the bag 6.

FIGS. 8a to 8 f show various arrangements of vents and spacers. In FIG.8a, the side wall 100 of the container has spacers 102 running from topto bottom, with three rows of vents 104, 106, 108 arranged between thespacers.

In FIG. 8b, the spacers are discontinuous and form three rows 120, 122,124, with a pair of vents 126, 128, 130, 132 being located between eachpair of adjacent spacers in the upper two rows of spacers 120 and 122.

In FIG. 8c, the three rows of spacers 140, 142, 144 are staggered, andvents 146, 148, 150 are located only between the spacers in the upperlayer. In this case, there are three vents between each spacer.

In FIG. 8d, there are only two rows of spacers 160, 162, and thevertical distance between the spacers is approximately one and a halftimes the height of the spacers. In this embodiment, vents 164, 166 arelocated between only the top layer of spacers 160.

In FIG. 8e, the outer receptacle 180 is provided with both full lengthspacers 182 and, at the lower end of the receptacle, shorter spacers184. Horizontally oriented vents 186 are located at the upper end of thereceptacle.

In FIG. 8f, the outer receptacle is provided with spacers 190 which arestaggered both in the vertical and horizontal directions. In thisembodiment, there are no vents in the side walls of the outerreceptacle.

It will be appreciated that in the embodiments shown in FIGS. 8c to 8 f,and to some extent also in FIG. 8b, effective ventilation of thecontainer will depend on the presence of vents in the base of the outerreceptacle (not shown). Such vents can, of course, also be present inthe base of the container shown in FIG. 8a, and indeed preferably arethus present.

FIG. 9 illustrates a further embodiment of the invention in which theouter receptacle 202 is provided with two rows of vents 210, arranged ingroups of three and separated by generally vertically aligned spacers208. The inner receptacle, which can be for example a Kraft paper sack,has been omitted from the drawing to assist clarity. At the lower end ofthe outer receptacle 202, the bottom wall 205 is provided with aplurality of vent holes 213 interspersed between an array of upstandingspacers 217 of generally rectangular (e.g. square) plan. The spacers 217serve to space the inner receptacle away from the bottom wall 205 andenable air to pass through the vents 213 and up through the containerbetween the inner and outer receptacles. At the upper end of thereceptacle, a lid 203 is provided. Lid 203 is hingedly attached to theouter receptacle and can be opened to allow material to be introducedinto the container. Also hingedly attached to the outer receptacle 202is a retaining ring 219 which serves to retain the inner receptacle inplace. In the drawing, the open positions of the lid 203 and retainingring 219 are shown by means of dotted lines.

A still further embodiment of the invention is illustrated in FIGS. 10and 11. In this embodiment, only the outer receptacle of which is shown,there are four rows of vents 310 a, 310 b, 310 c and 310 d, two rowsbeing arranged around the upper end of the container and two rows beingarranged around the lower end of the container. As with the containersof the other embodiments, the container has an array of spacers 308extending up the inner surface of the outer receptacle 302. At the lowerend of the outer receptacle, a ventilation grid 313 having vents 313 apermits liquids discharged from the inner receptacle (not shown) todrain into a removable tray 314. The structure of the removable tray andthe lower end of the outer receptacle can be seen with greater clarityin FIG. 12 which is an enlarged view of a lower corner of the outerreceptacle.

In common with the embodiment of FIG. 9, the outer receptacle is closedat its upper end by means of a lid 303 which is hingedly attached to theouter receptacle. A retaining ring 319, which serves to retain the innerreceptacle in place, is also hingedly attached to the outer receptacleand can be pivoted into an open position (as shown by means of thedotted line in FIG. 11) to allow the inner receptacle to be replaced asrequired.

By virtue of the foregoing properties, the container of the invention isable to exploit the properties of the inner bag by providing an aerobicenvironment meeting the requirements of the bag and its contents. Thecontainer of the invention achieves its object by the carefulpositioning and sizing of a plurality of vents, allowing the circulationof air in the container, arranged between a plurality of spacers whichhold the one or more bags away from the inside face of the walls of theouter receptacle. As indicated above, the bottom of the container cancontain a vent or plurality of vents and spacers, which can be combinedwith one or more integral or detachable trays to catch liquids and/orsolids.

It will be appreciated that the foregoing description is merelyexemplary and that numerous modifications and alterations can be made tothe particular embodiments shown in the drawings without departing fromthe principles underlying the invention. All such modifications andalterations are intended to be embraced by this Application.

What is claimed is:
 1. A container comprising an outer receptacle and,disposed therein, an inner receptacle in the form of a bag; the bagbeing permeable to gases; the outer receptacle having a plurality ofspacers extending inwardly from an inner surface thereof, and aplurality of vents in one or more walls of the outer receptacle; thespacers serving to support the inner bag such that it is spaced apartfrom the inner surface of the outer receptacle; and the vents serving toallow air to circulate between the bag and the outer receptacle.
 2. Acontainer according to claim 1 wherein the outer receptacle has one ormore vents formed in at least one wall thereof.
 3. A container accordingto claim 2 wherein the outer receptacle has one or more vents formed ina base thereof.
 4. A container according to claim 2 wherein the ventsare provided adjacent at least 50% of the spacers.
 5. A containeraccording to claim 4 wherein the vents are provided adjacent at least75% of the spacers.
 6. A container according to claim 2 wherein thevents are elongate in form.
 7. A container according to claim 6 whereinthe vents are arranged in a plurality of substantially horizontal rowsaround the outer receptacle.
 8. A container according to claim 7 whereinthe rows are substantially parallel with respect to each other, and aredisposed such that the vents are in substantially vertical alignment. 9.A container according to claim 8 wherein the vertical distance betweenrows of vents is between 0.5 and 3 times the height of each vent in apair of vertically adjacent rows.
 10. A container according to claim 9wherein the horizontal distance between adjacent vents in a row of ventsis between 1 and 10 times the width of the vent.
 11. A containeraccording to claim 2 wherein the configuration and arrangement of thespacers is such that, together with the inner surface of the outerreceptacle and an outer surface of the inner receptacle, elongate ductsare created which serve to channel convection currents between the innerand outer receptacles.
 12. A container according to claim 11 wherein theelongate spacers extend in a substantially upwards direction.
 13. Acontainer according to claim 12 wherein said spacers includediscontinuities, and wherein the spacers are arranged in rows insubstantially vertical alignment.
 14. A container according to claim 1wherein the spacers are in the form of elongate ribs.
 15. A containeraccording to claim 1 wherein the spacers are from 0.25 cm to 8 cm.
 16. Acontainer according to claim 1 wherein the spacers have a width varyingfrom 0.25 cm to 8 cm.
 17. A container according to claim 1 wherein theouter receptacle is provided with a base having at least one vent formedtherein.
 18. A container according to claim 1 wherein the innerreceptacle is formed from a paper material, or a permeable polymeric orcomposite material.
 19. A container according to claim 1 wherein theouter receptacle comprises suspension means for securing the innerreceptacle to an upper end thereof, the suspension means being arrangedto hold the inner receptacle in an open configuration.
 20. A containeraccording to claim 1 wherein the container includes a base, said basebeing provided with one or more spacer elements for supporting the bag.21. A container according to claim 1 wherein at least one of the outerreceptacle and the bag includes means for repelling insects or smallcreatures.